Huh. Years ago I tried pocket casts, podcast addict, and podcast republic. I chose republic since it fitted my usage better. They have not gone subscription. I bought the app once years ago and that's been it. I'm not sure if the free version is ad supported.

I would have been very disappointed had I bought pocket casts and then found I was locked out of some features later. I have dropped other apps that did that, after leaving them bad reviews